Means for protecting grate-bars in boilers.



No. 891,068. PATENTED JUNE 16, 1908.

0. HOFFMAN.

MEANS vPOR PROTBGTING GRATB BARS IN BOILERS.

APPLICATION FILED 11213.24, 190e.

ATTEST INVEN'mR b OLLo Hoffman.

. BY www ATM THE NoRms PErERs ca., WASHINGTON. n. cA

UNITED STATES PATENT OFFICE.

OTTO HOFFMAN, OF CLEVELAND, OHIO.

MEANS FOR PROTECTING GRATE-BARS IN BOILERS.

Application filed February 24, 1908.

To all whom it may concern:

Be it known that I, OTTO HOFFMAN, a citizen of the United States, residing at Cleveland, in the -county of Cuyahoga and State of Ohio, have invented certain new and useful Improvements in Means for Protecting Grate-Bars in Boilers, and do declare that the following is a full, clear, and exact description of the invention, which will enable others skilled in the art to which itappertains to make and use the same.

My invention relates to improvements in means for protecting grate-bars in boiler furnaces and for keeping said bars clean, and the invention consists in the construction and combination of parts substantially as shown and described and particularly pointed out in the claims.

In the accompanying drawings, Figure 1 is a front elevation of a boiler with three several furnaces and grates therein, and Fig. 2 is a sectional elevation lengthwise of one of said grates.

The idea of the invention herein is to protect the grate-bars B of a boiler furnace from burning out and to prevent clinkers from forming upon said bars as Well as to assist in maintaining clean iires and thereby promoting combustion and saving fuel. To these ends the invention comprises a furnace with grate or grate-bars B, such as are found under marine boilers, or others, and a pair of steam feeding pipes P, arranged transversely of the furnace beneath the same at the front and rear respectively, the said pipes connecting with a supply pipe S at their ends, and which has a live steam source at the top of the boiler. The said pi es are relatively small, pipe S being usua y of about three quarter size, while pipes P are about half inch size, and the perforations of pipes P are at their inner sides and not along their top, so that the steam issuing through or from the small perforations 2 therein will be thrown into the intervening area beneath the grate and diffused in said area and incorporated with the air that is drawn through the grate to supply combustion. Furthermore, the

supply or quantity of steam flowing to andv through said pipes P is subject to regulation as to quantity and pressure so as to get just the quantity wanted in any given case, and to this end I provide a pressure regulatoror reducing valve R therein having an armfl with a weight 5 adapted to governl the pressure in said pipe S. Thus, assuming that the Specification of Letters Patent.

Patented June 16, 1908.

Serial No. 417,248.

boiler ressure is 180 pounds, the said regulator w' diminish the same say to 60 pounds or less in said pipe, so that both the volume and the pressure of steam may be controlled in this way.

Now, it is to be further understood that dry steam is to be used exclusively and not wet or exhaust steam nor jets of water, as neither of these would enter into combination with the air as dry steam does in my manner of use, and both would unduly moisten the grate-bars if they were thrown against said bars, thus corroding the bars and largely defeating the objects I have in View. Furthermore neither wet steam nor water could be used by horizontally arranged perforations 2 as employed in my invention because they would not .mingle with the air as dry steam does and the moist deposits would be very objectionable. Hence to practice my invention, care must be taken that only dry steam is brought to pipes P, which will not fail to accom lish all the objects sought thereby when du y regulated in its flow, and as an expert engineer will soon see is best adapted to a given kind of fuel and other conditions that may be peculiar to a particular place of use.

Now as an illustration of the operating value andeffect of this device I may say that prior to the introduction of my invention in connection with certain marine boilers it has been a common experience that a set of grate-bars would literally burn out and have to be re laced in four to siX weeks, and sometimes after a single round trip of a boat. But with this device installed in the same boat with the same kind of grate-bars the said bars have lasted an entire season and firing was rendered much easier and the quantity of steam derived from a given quantity of fuel was notably increased, so that greater speed was possible than formerly when said device was not used. Em-

hasis is also to be laid on the particular ocation and number of said pipes P, because the service they are to render according to my invention appears to be best subserved with two pipes only, and the rear pipe is in osition to keep the bridge wall W clear of c inkers as well as contributing to cleansing and preservation of the grate-bars.

What I claim is 1. In steam boilers, a boiler furnace having a horizontal grate, in combination with a pair of steam pipes arranged on the same plane transversely beneath the front end and the rear end of said grate, respectively, and in close proximity thereto, and provided 'along their parallel meeting faces with perforations for the delivery of steam toward each other in the same plane beneath the grate and centrally between the ends thereof.

2. A furnace and boiler having a grate, steam pipes provided with'horizontally arranged perforations along their inner sides oppositely and arranged beneath the front and the rear respectively of said grate, and whereby steam is distributed uniformly to said grate from the yends to the center thereof, la supply pipe connected with said 15v boiler adapted to furnish steam to said pipes, and a pressure regulator located in said steam supply pipes adapted vto regulate the steam in said steam distributing pipes.

In testimony whereof sign this specili- 20 cation in the presence of two witnesses.

OTTO HOFFMAN.

Witnesses:

E. M. FISHER, F. C. MUssNER 

